CN2648076Y

CN2648076Y - Valve actuating mechanism for single-cylinder four-stroke engine of motorcycle

Info

Publication number: CN2648076Y
Application number: CN 03252833
Authority: CN
Inventors: 郝宁宁
Original assignee: Chongqing Zongshen Technology R & D Co ltd
Current assignee: Chongqing Zongshen Engine Manufacturing Co Ltd
Priority date: 2003-09-17
Filing date: 2003-09-17
Publication date: 2004-10-13
Anticipated expiration: 2013-09-17

Abstract

The utility model relates to a motorcycle single cylinder four-stroke engine push rod which is provided with an upper and a lower swing arm and is equipped with a cam type gas distribution mechanism at the lower part. The utility model comprises a camshaft which is arranged in a camshaft chamber, the lower swing arm which is driven by the camshaft, a push rod which is pushed by the lower swing arm, the upper swing arm which is pushed by the push rod and a valve stem which is pressed by the upper swing arm, as well as two cams which are arranged on the camshaft in parallel. The gas distribution mechanism can carry out the single adjustment of any angle of an intake advance angle, an exhaust advance angle, an intake delay shut angle and an exhaust delay shut angle through the cams, as well as the single control of the intake time-area value and the exhaust time-area value of a valve.

Description

The distribution device of motorcycle single-cylinder four-stroke engine

Technical field

The utility model relates to a kind of distribution device of motorcycle engine, particularly the single-cylinder four-stroke engine push rod, be with lower shake-changing arm, underlying cammingly distribution device.

Technical background

At present, the four-stroke CG series motorcycle motor that domestic most of motorcycle engine enterprise produces, its distribution device is generally band push rod and last lower shake-changing arm, underlying cammingly, the mainly lower shake-changing arm that drives by the camshaft that is positioned at camshaft chest, by camshaft, the push rod that promotes by lower shake-changing arm, the upper rocker arm that promotes by push rod, and form by the valve stem that upper rocker arm presses, its cam that is positioned on the camshaft of this kind distribution device is a single cam, it acts on two lower shake-changing arms simultaneously, with the unlatching and the closure of control intake valve and exhaust valve.

Distribution device is motorcycle engine inner control valve opening and closed mechanism, and its port timing has very big influence to the external characteristics of ventilation quality, pumping loss, charging efficiency idle stability, noxious emission and the motor of motor.The angle is closed in intake advance angle and air inlet that the design of port timing should make intake valve have a certain size late, the angle is closed in the exhaust advance angle and the exhaust that make exhaust valve have a certain size late, and advance angle and to close the angle late be to realize by the cam that changes on the camshaft, three kinds of methods of general employing: the one, change cam profile, cam profile is by basic circle, ascent stage and descending branch are formed, the starting point that changes the ascent stage can change intake advance angle, because the underlying cam of distribution device is a single cam, it is simultaneously to two rocking arm effects, so change of intake advance angle, also must cause the change of exhaust advance angle, equally, if the end of change molded lines decline end promptly changes air inlet and closes the angle late, then must cause exhaust to close the change at angle late; Another method is the relative position that changes camshaft axis and lower shake-changing arm axis, and same because single cam makes it be equivalent to the while and changes together that the angle is closed in intake advance angle, exhaust advance angle, air inlet late and the angle is closed in exhaust late; The third method is that cam is rotated to an angle with respect to original position, and this method is the same with second method will to be changed advance angle simultaneously and close the angle late.Close in the angle any one jiao late and adjust so above-mentioned three kinds of methods all can not be separately closed angle and exhaust late to intake advance angle, exhaust advance angle, air inlet, thereby cause by adjusting the port timing that cam is difficult to reach artificer's expection.

In addition, change the ascent stage or the descending branch of cam profile, face amount in the time of will changing air inlet and exhaust together simultaneously (is the integral value of gas passageway cross-sectional area function f (t) to time t, the inlet and outlet passing capacity that has reflected valve mechanism), in the time of can not be to air inlet when face amount and exhaust face amount control separately, be difficult to obtain desirable charging efficiency.

The model utility content

Technical problem to be solved in the utility model provides a kind of distribution device of motorcycle single-cylinder four-stroke engine, make it close angle and exhaust late to intake advance angle, exhaust advance angle, the air inlet of valve and close in the angle any one jiao late and adjust separately by the cam on the camshaft, and during to the air inlet of valve when face amount and exhaust face amount control separately.

The distribution device of motorcycle single-cylinder four-stroke engine described in the utility model, the lower shake-changing arm that comprises the camshaft that is positioned at camshaft chest, drives by camshaft, the push rod that promotes by lower shake-changing arm, the upper rocker arm that promotes by push rod, and the valve stem that presses by upper rocker arm, be set side by side with two cams on camshaft, it controls two lower shake-changing arms respectively.

One on two cams are intake cam, and another is an exhaust cam, and it acts on intake rocker and exhaust rocker arm respectively, thereby control the unlatching and closure of intake valve and exhaust valve respectively.

Distribution device described in the utility model is owing to have intake cam and exhaust cam on its camshaft, it is respectively to intake rocker and exhaust rocker arm effect, the two controls intake valve and exhaust valve respectively, and face amount all can be controlled separately by intake cam when angle and air inlet were closed in intake advance angle, air inlet late; Face amount all can be controlled separately by exhaust cam when angle and exhaust were closed in exhaust advance angle, exhaust late, close in the angle any one jiao late and adjust so the artificer can be as required closes angle and exhaust to intake advance angle, exhaust advance angle, air inlet separately late, be easy to realize the distribution device expection port timing and the time face amount.

Description of drawings

Now in conjunction with the accompanying drawings the utility model is described in further detail.

Fig. 1 is the schematic representation of a kind of concrete structure of distribution device of motorcycle single-cylinder four-stroke engine described in the utility model;

Fig. 2 looks intention for the K of lower shake-changing arm among Fig. 1 and camshaft to amplification.

Embodiment

As shown in Figure 1 and Figure 2, the distribution device of this motorcycle single-cylinder four-stroke engine, the lower shake-changing

arm

2,6 that comprises the camshaft 1 that is positioned at camshaft chest, drives by camshaft 1, promote by lower shake-changing

arm

2,6 push rod 3,3 ', by the upper rocker arm 5,5 of push rod 3,3 ' promotion ', and by the valve stem 4,4 of upper rocker arm 5,5 ' press ', on camshaft 1, be set side by side with 7 two cams of intake cam 8 and exhaust cam, it controls two lower shake-changing

arms

2,6 respectively, be intake cam 8 control air inlet lower shake-changing arms 2, exhaust cam 7 control exhaust lower shake-changing arms 6.By changing intake cam 8 or exhaust cam 7, can close angle and exhaust late to intake advance angle, exhaust advance angle, the air inlet of valve and close in the angle any one jiao late and adjust separately, and during to the air inlet of valve when face amount and exhaust face amount control separately.

Claims

1, the distribution device of motorcycle single-cylinder four-stroke engine, the lower shake-changing arm (2,6) that comprises the camshaft (1) that is positioned at camshaft chest, drives by camshaft, the push rod (3,3 ') that promotes by lower shake-changing arm, the upper rocker arm (5,5 ') that promotes by push rod, and the valve stem (4,4 ') that presses by upper rocker arm, it is characterized in that: be set side by side with two cams (7,8) on camshaft, it controls two lower shake-changing arms (6,2) respectively.